MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To decrease the coefft. of dynamic friction and to improve running property by forming projections on the surface of a back coat layer in such a manner that the projections having about 2-30nm height exist at a sparse ratio of about 20X10<3> pieces/mm<2> on the surface thereof. CONSTITUTION:The carbon black-contg. layer which is the back coat layer is so constituted that the projections having about 2-30nm height exist at the sparse ratio of about <=20X10<3> pieces/mm<2> (more preferably about >=5X10<3> pieces/mm<2>) on the surface thereof. The carbon black-contg. layer is formed by first adding about 60-90% of the total amt. of the carbon black to be added to the paint, executing the dispersion operation and adding the remaining carbon thereto after the dispersion operation is once stopped in the mid-way of the prescribed dispersion time or while the dispersion operation is continued. The carbon-contg. paint is produced by the stage for executing the dispersion by continuing the remaining dispersion time. The resultant carbon black-contg. paint is coated on the surface of a substrate on which a magnetic layer is not formed and the above-mentioned layer is obtd.